Radiation redirecting external case for portable communication device and antenna embedded in battery of portable communication device

ABSTRACT

An antenna or set of antennae for a wireless device is provided by embedding the antennae into the battery case or generally the surface area of a wireless phone. The antenna connections are through the battery&#39;s connections to the wireless device. The antenna can be located at the back surface of the battery or the rear surface of a wireless phone, facing away from the user. An RF shielding device can be embedded into the battery and configured in relation to the antenna such that the RF field intensity and the consequent specific absorption rate for the user is lowered while the outgoing signals of the wireless device remain fully adequate for the function of the wireless device. This feature is preserved for a multi-band operation because a digital phase shifter is used between two radiating antennae. An external case is used as a complement to the wireless phone.

CROSS REFERENCE TO RELATED APPLICATIONS AND CLAIM FOR PRIORITY

This application is a continuation of U.S. patent application Ser. No.12/614,132, entitled “RADIATION REDIRECTING EXTERNAL CASE FOR PORTABLECOMMUNICATION DEVICE AND ANTENNA EMBEDDED IN BATTERY OF PORTABLECOMMUNICATION DEVICE,” filed on Nov. 6, 2009, which claims priority toand the benefit of Provisional Application Ser. No. 61/112,141 filedNov. 6, 2008, and Provisional Application Ser. No. 61/158,551 filed Mar.9, 2009, all of which are incorporated herein by reference in theirentirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates generally to portable communication devices suchas cell phones, smart phones and similar handheld devices, andimprovements thereto. In particular, this invention providesimprovements in antennas and RF shielding of such devices, the embeddingof an antenna into the removable battery of a portable communicationdevice, or any large surface area inside a phone, facing a directionaway from the user, to redirecting RF radiation away from the body of auser, and to several methods of exploiting technical advantages thatresult from embedding an antenna into the battery.

2. Background

Design requirements of cellular phones and smart phones are placing anever increasing premium on the available space within these devices astheir functions become more diverse, ranging from the original basicfunction as a wireless telephone to a music player, video player,handheld computer, wireless internet device for browsing the web,retrieving email and downloading or uploading files, a still camera, avideo camera, a GPS device, a navigation system, etc. These functionsbring with them greatly increased demands upon the antenna and generallyrequires more radiation power for transmission, which must serve up tofive frequency bands while occupying less space than ever beforeavailable for the antenna.

In addition, RF radiation from mobile phones is becoming of greaterconcern as a health risk, and addressing this issue in the design of theantenna while the space within the phone is reduced poses a particularlydifficult challenge, as the only effective methods of significantlyreducing RF radiation in the direction of the user, while allowing fullpower RF signal away from the user, require some additional space forthe antenna.

The FCC requires limiting the radiation from a portable communicationdevice (such as a mobile or cellular telephone) that is directed towardsa user's head (Specific Absorption Rate, or SAR). Each year the FCCtends to lower the permitted level further. One of the reasons issafety. At the same time, as wireless communications technologyadvances, the mobile phone device has taken on the function of ahand-held computer with more data-intensive functions, requiring highrates of data transfer between the cell phone and the base stationtower. It would be beneficial to the improved function of cell phones tobe able to increase the power output of the antenna, but FCC regulationswill not allow increased SAR.

The Smart Phone (.iPhone, BlackBerry, etc.), for example, has aninternal antenna(s) located at both the lower and upper parts of thephone, bordering the display area. The space for an antenna is usuallylimited to 1 cm times the width and thickness of the phone. The antennais situated close to the back surface of the phone, on the side oppositeto the user.

SUMMARY OF THE INVENTION

According to a first embodiment, the present invention dramaticallyincreases the effective space for the antenna and provides highlyeffective shielding and RF radiation redirection away from the user,while actually increasing the available space within the phone casing.The invention incorporates the antenna into the battery such that theantenna lies on the side of the battery facing away from the user, wherethe battery is attached to the back of the phone facing away from theuser. The battery's electrical connections are increased to include allthe needed antenna leads into the phone's circuits. All batteriesdesigned for a particular model of phone would feature the antennabuilt-in.

One advantage of this design is to afford far more space for the complexantennas of the future, aiding in their optimization. Separate antennascan be employed within the battery, utilizing the relatively larger areaavailable on the battery to provide separation of antennas of differentfrequencies and functions, thereby reducing interference between theantennas. Another important advantage of this configuration is that itpermits optimization of an RF shielding design for wireless phones. Thethickness of the battery can serve to provide the needed space betweenthe antenna and a tuned RF shielding element placed within the batteryon the side nearest the user, with the lithium ion core or otherfunctional storage medium of the battery lying between the shielding andthe antenna. The resulting spacing between the RF shielding and theantenna is optimally one-quarter of the wavelength of the transmissionsignal. This goal can be aided by the use of a layer of dielectricmaterial between the RF shielding and the antenna, but is stillextremely difficult to achieve in the small space allowed inside thephone case. By designing the battery such that the thickness of thebattery's storage medium results in the correct spacing for the tuningof the RF shielding, and by grounding the shielding through a connectorfrom the battery to the phone's ground circuit, and by designing the RFshielding itself to optimally redirect the RF radiation away from theuser while leaving undiminished the desired signal directed away fromthe user, a unique benefit of significant reduction in RF absorption bythe user's body can be achieved.

An alternate way of redirection is to use two antennas phasedappropriately to radiate waves in a direction away from the user. Thiscan be achieved in two ways:

-   -   1. Place two antennas one on each side of the battery. Each        antenna is connected to the output power. The phase between        these antennas is controlled digitally to give the optimum        direction outward. Micro-processor with very low power        requirement (microwatt) is available for this digital control.        The power for such control can be derived from capturing the        radiation power from the phone.    -   2. This configuration is ideal for multiple-band applications.        For each frequency used the phase is programmed to give the        optimum propagation characteristics. This will make it        unnecessary to have a material of high dielectric constant.

The same principle can be used where one antenna is located in the cellphone case and another antenna inside the phone or on/in the battery. Ingeneral, two or more antennas are preferred to direct the radiation froma wireless phone.

According to a second aspect of the invention, radiation from a portablecommunication device is directed away from the user such that there isminimum effect on the performance of the device. The end result is a lowSAR and an unchanged TRP (Total Radiation Power). This is accomplishedby coupling radiation from the antenna inside a wireless phone to anexternal case. The external case is provided with a shield comprising ametallic surface that is corrugated. Such a shield may also be installedinside the wireless device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an antenna embedded into a battery and the antennaconnections from the battery casing to the phone circuits, with theantenna designed as a compact unit located at the upper end of thebattery.

FIG. 2 shows an antenna embedded into a battery and the antennaconnections from the battery casing to the phone circuits, with theantenna designed as a thin flat unit located on the planar surface inthe back of the battery.

FIG. 3 shows separate antennas of different frequency and purposelocated apart from one another in separate areas of the battery.

FIG. 4 shows an RF radiation shield embedded into the battery, such thatthe shielding is on the side of the battery nearest the user while theantenna in on the side of the battery farthest from the user in the sameflat planar configuration as shown in FIG. 2. Also shown in FIG. 2 isthe ground connection for the shielding through the battery to thephone's ground circuit.

FIG. 5 shows an exploded view of the battery with the antenna, theelectrical storage medium, the RF shielding, and the dielectric layersidentified, as well as the electrical connections for the battery power,the antenna and the RF shielding ground.

FIGS. 6, 7A and 7B show various views of a protective external wirelessphone case provided with a passive coupling antenna incorporated intothe back of the case in accordance with a first embodiment.

FIG. 8 shows a beam antenna combined with a shield having a metallicsurface that is corrugated.

FIG. 9 shows layer of highly conductive corrugated metal shield of aspecific design is, optionally, combined with a layer of absorptivematerial of a specific frequency range.

FIGS. 10 and 11 show various views of a protective external wirelessphone case provided with a passive coupling antenna incorporated intothe back of the case in accordance with a second embodiment.

FIG. 12 shows RF redirection material being integrated into the internaldesign of a wireless device.

FIG. 13 is a diagram illustrating a multi-band antenna located insidethe wireless device, the phase of which can be controlled by amicroprocessor to correspond to use of different communication frequencybands.

FIG. 14 is a diagram illustrating the use of phase control of antennapropagation to direct electromagnetic radiation in a direction away fromthe user of the wireless device.

DETAILED DESCRIPTION OF THE INVENTION

Antenna Embedded into Battery or Wireless Devices

According to first aspect of the invention as shown in FIG. 1, anantenna 10 for a wireless device 14 is embedded into the battery 12,such that the space inside the wireless device formerly occupied by theantenna is available for other components, and the antenna is connectedto the wireless device's antenna circuit by electrical contact surfaces12 a on the battery casing that contact corresponding surfaces 12 b onthe phone case, in the same manner as the power connections are madefrom the battery to the phone's power circuit. The antenna may be ofcompact design and fitted into one end or side of the battery casing, asshown in FIG. 1. Optionally, the antenna may be made thin and flat andmay be placed on the broad flat plane parallel to the battery's energystorage core as shown in FIG. 2 as antenna 20.

As shown in FIG. 3, separate antennas 30 and 32 of different frequenciesmay be provided on the battery located apart from one another in variousareas within the battery. For example, one antenna 30 may be designedfor quadband performance, and another separate GPS antenna 32 may beadded in another area of the battery case with its own circuit andconnections through to the wireless device.

In another embodiment of the invention as shown on FIG. 4, an RF shield40 is embedded into the battery such that the energy storage corematerial 42 of the battery lies between the shielding 40 and the antenna20. The antenna is grounded to the wireless device's ground circuit bycontacts 44 in the same manner as the antenna connection describedabove. The battery is designed such that the thickness of the energystorage core causes the spacing between the RF shielding and the antennato be one-quarter of the wavelength of the transmission signal. Thistuning of the relationship of the RF shielding to the antenna can beenhanced by the embedding of a layer of dielectric material between theRF shield and the antenna.

The main feature of this design for a battery case is that the antennafor the wireless device is embedded within the battery rather thaninside the wireless device. Various configurations of the antenna withinthe battery case are possible and obvious to any person of ordinaryskill in the art.

In the embodiment of this invention wherein an RF shield is embeddedinto the battery case, only the side of the battery facing the usercontains the shielding while the side away from the user is made fromnon-conducting or low-conductive materials allowing the EM wave topropagate outward towards the cell phone tower without suffering anyattenuation.

Incorporation of this RF shield inside the battery will aid insatisfying the FCC requirement limiting the radiation that is directedtowards the user's head (Specific Absorption Rate, or SAR). Over timethe FCC may tend to lower the permitted SAR level even further. At thesame time, as wireless communications technology advances, the cellphone has taken on the function of a hand-held computer with moredata-intensive functions, requiring high rates of data transfer to andfrom the cell phone tower. While it is beneficial to the improvedfunction of cell phones to increase the power output of the antenna, FCCregulations will not allow such an increase in the SAR if the radiationis isotropic. The device of the present invention wherein the radiationis redirected away from the user and towards the base station fulfillsboth the requirements of the FCC and the technical communicationrequirements of ever increasing data rates in mobile entertainment andcommunication devices.

FIG. 5 further illustrates the concept of a “smart” case 50 for awireless communication device. A smart case is one which is connected toa communication device such as a cell phone through a connector such asthe lower multiple pin connectors on the body of the cell phone. Itexpands the capability of any phone by providing more usable space for asecond antenna, a manual charging system, an earpiece (which does notcarry RF into the ear), or additional memory in addition to itsfunctioning as a carrying case. Examples of these multiple functions areshown in FIG. 5, although it should be emphasized that there is a greatdeal of flexibility in the arrangement of these units mentioned above,and the arrangement of FIG. 5 thus is not limiting of the scope of thisinventive concept.

The advantage of this smart case is to always improve a given cell phonewhose function is to transmit and receive signals, while the case canalways upgrade the function of a cell phone. One of the most importantfunctions of such a case is to provide a second antenna which if phasedproperly will provide the redirection feature without the use of ahigh-dielectric material. In order to make a multiple band antennadirectional it is important to use a phased array so that radiationalways will be emitted from one side of the phone.

According to a second aspect of the invention, radiation is coupled fromthe antenna inside a wireless phone to an external case where thedistribution of radiation can be better managed. Several arrangements ofdirecting RF radiation away from the user's head by the appropriateplacement of metallic loops and other parasitic elements are presented.This can take the form of arrays of dipole antennas, conducting loopsand conducting plates with insulators or dielectrics. The generalconcept is to couple the radiation from the internal antenna on the sidefacing the user to the opposite side of the device, where there issufficient space inside an external case to direct such radiationoutward and away from the user. The coupling must be designed to directthe radiation without causing a drop in the output of the externalamplifier. From an engineering point of view the impedance seen by theoutput amplifier should not change. From a physicist's point of viewthere should be minimum radiation power reflected back on the radiatingantenna of the cell phone.

In one preferred embodiment of this aspect of the invention, “couplingantennas” are used to direct radiation from the internal antenna of awireless phone to a large surface of a carrying case such that there isminimum radiation towards the user and maximum radiation away from theuser. It is important to note that this coupling method does not requirean actual physical connection between the case and the interior of thephone. However the position of the coupling antenna with respect to theinternal antenna is critical. Through a series of coupling loops, Yagiantennas or patch antennas, the radiation is further directed away fromthe user's head which is absorptive and towards his surroundings forcommunication to cell towers. The materials used for coupling andre-directional elements are generally made out of materials of highelectric conductivities, although dielectric materials are also used toachieve optimal physical spacings.

In the preferred embodiment of the invention as shown in FIGS. 6, 7A and7B, a protective external wireless phone case 4 is provided with apassive coupling antenna (which may be a Yagi, loop or patch antenna)incorporated into the back of the case, on the side away from the user.This antenna works as a directional antenna consisting of an array of adipole and additional closely coupled parasitic elements (e.g. areflector 2 and one or more directors 2) and directs the radiation fromthe internal antenna 1 up, out and away from the phone. In thispreferred embodiment the beam antenna may also be substituted by a loopor patch antenna.

In another embodiment of the invention as shown in FIG. 8, the beamantenna may be combined with a shield 80 comprising a metallic surfacethat is corrugated, giving rise to many image dipoles, thereby providinga wide pattern of radiation. The particular shape and size of thecorrugations is critical, the objective being to disperse the reflectedradiation as widely as possible. The corrugations are preferably ofcomparable size or smaller than the spacing of the shield from theantenna.

In an alternate embodiment of the invention as shown in FIG. 9, thelayer of highly conductive corrugated metal shield 80 of a specificdesign is combined with a layer of absorptive material 90 of a specificfrequency range, inserted between the internal antenna and the user,such that with the phone inserted into an external case the materialswould be placed as indicated.

The redirection of RF radiation away from the user's head may also beachieved by the use of a properly located passive beam antenna as shownin FIGS. 10 and 11, with or without the corrugated shield of highlyconductive metallic material, and with or without a layer of absorptivematerial.

A main feature of this invention, whether as a passive directional beamantenna alone, or in combination with a passive re-directional shieldincorporated in an external case for a wireless phone, or suchcombination incorporated internally in a wireless phone device, is thatthe invention directs/redirects radiation away from the user and out ofthe phone towards a cell tower, reducing SAR without adversely affectingTRP. It does this with a combination of a directional antenna andre-directive shield integrated within a case of non-conducting orlow-conductive materials (variously of silicon, plastic, cloth, etc.)that allow EM waves to propagate outward towards the cell phone towerwithout suffering any attenuation.

The same RF redirection would be the result of the material(s), in thesevarious embodiments, being integrated into the internal design of thewireless device, as shown in FIG. 12.

The invention may also be embodied in an active case, where the powerthat drives the external antenna embedded in the external case comesfrom the cell phone's internal battery via the phone's built in powerport. The power can also come from solar cells embedded into theexternal case. It can also come from mechanical motion of apiezoelectric or other similar mechanical to electrical generator.

The invention includes a directional beam-antenna (Yagi, loop or patch)integrated into the external case on the back side of the phone awayfrom the user, floated within the external case with a general tolerancefor placement optimally within +/−0.020″ (+/−0.5 mm). This antenna worksas a directional antenna consisting of an array of a dipole andadditional closely coupled parasitic elements (a reflector and one ormore directors). These elements are made of specific planar metalmaterial (copper or gold, for example). The dipole in the array isplaced over the phone's internal antenna, effectively coupled byproximity and within a specific tolerance of placement, but optimally at5%, and driven by said internal antenna. Another element, 10% longer,operates as a reflector. Other shorter parasitic elements are added infront of the dipole as directors. Elements arranged optimally atapproximately a one-quarter-wavelength mutual spacing and beingprogressively slightly shorter than a half wavelength, optimallypositioned within a 10% tolerance, direct signals of increasingly higherfrequencies onto the active dipole. The beam-like antenna hasdirectionality, directing radiation away from the reflector through thedriven element and out via the directors in the top of the wirelessdevice, producing a chimney effect.

The directional antenna may also be a loop or patch antenna where saidantenna is on the back of the phone, away from the user's head, placedoptimally 3 mm below the plane containing the iPhone antenna. The loopis offset along the X-axis so that the edge is between the ground sheetand the antenna element. If a patch antenna is used, the patch directoris square in shape, and each side is optimal in length. These are freespace lengths, corrected for dielectric constant (velocity factor). Thepatch director functions like the loop director.

The metallic surface is preferably non-planar so that theelectromagnetic waves radiated by antennas are reflected into a widelyscattered area. The non-planar surface causes reflections of radiationfrom a single dipole into a much wider area than a planar surface and asingle dipole. The metallic surface may be corrugated, curved, or may befolded.

This highly conductive metal imbedded in the external case to reflectthe radiation should be corrugated in a specific way (e.g. rows,chevrons, pyramids), to a specific height and width of corrugation. Itshould be of a specific thickness; optimally, greater than the skindepth of the EM wave at the cell phone frequency. The metal shield mayalso be flat. The placement on the face of the wireless phone withrespect to the internal antenna(s) is specific.

Another condition for efficiency is that the separation between themetal layer and the enclosed antenna should be occupied by a broadbandresonant absorptive material having a specific frequency range that isloaded for predetermined loss tangents and that functions on animpedance matching principle. The material is placed over specific areasto limit radiation to the user. However the case is able to redirectradiation effectively, if not optimally, even when the conditions aboveare not met.

Although the foregoing features described above deal with antennaelocated in the lower part of the phone, it will be apparent that thesame concept can be applied to antennas located in the upper part orother areas of the phone.

A simplification of applying the radiation redirection and shielding canbe by use of adhesive patches applied directly onto the area over theantenna; a first patch over the antenna on the side opposite the user(i.e. toward the cell tower) and a second patch between the antenna andthe user. In this embodiment the beam antenna, the highly conductingcorrugated shield and, optionally the frequency-targeted resonantabsorptive layer, can be sandwiched between two non-conducting layers,one of which contains an adhesive surface to be applied directly ontothe phone. The user will receive the protection whether the case isapplied over it or not. It is apparent that this simplification can beapplied to any case and to any phone. Appropriate covering might benecessary to secure this patch in place for more permanent application.

Incorporation of the Shield During Manufacturing

Instead of a case described above, a passive coupling and redirectionunit can be installed inside a wireless device, provided the appropriatespacing is used between this coupling unit and the original cell phoneantenna. This is made possible by the fact that both the coupling loopand the Yagi directors can all be lined up in a plane with a thicknessof 1-2 mm.

Instead of using a case featuring the above described shield can bebuilt into the wireless device; either the beam antenna, alone, or incombination with the corrugated metallic shield, or in combination withthe absorptive frequency targeted, can be incorporated directly withinthe phone's structure. The plastic/metal housing of the phone facing theuser will have a liner with a conducting metal layer and, optionally, anabsorptive layer, separating the beam antenna, the metal layer and theinternal antenna. This has the advantage that the phone is complete withthe shield right from the factory.

Another effective method has emerged that is a hybrid approach,combining the passive redirection with the active driver amplifier andbattery in the external case. This method uses the cell phone antennaand power amplifier system as a wireless feed to the amplifier/antennasystem inside the external case. The final transmission power is to beradiated from an antenna inside the external case. Therefore, the cellphone system serves only as the low power driver, which couples to thefinal power amplifier (PA) for final transmission to cell stations.Since the antenna in the case can be a patch antenna with a ground planeoccupying a space greater than the radiating antenna, we should expectthe radiation pattern to be that of a patch antenna. The radiationpattern is hemispherical and will satisfy our goals of achieving a highdirectional TRP and at the same time low SAR.

As the base station tower receives a strong signal from the externalcase antenna, it signals the cell phone to lower its power. The cellphone antenna now radiates only a small amount of energy since it actsonly as a low-power drive to the external case system, which isperforming all the real transmission work. As the cell phone lowers itspower, its radiation towards the user will be correspondingly lower evenif a shield is not present. When a shield is included on the user sidethe radiation towards the user will be further reduced. In fact, theeffect of the passive shield of suppressing the TRP of the cell phone'santenna is now an advantage to us, as it will allow the Pong antenna tobe the dominant antenna. The efficiency of the cell phone's antenna isno longer critical, as it only needs to communicate with the externalcase's coupling antenna located a few millimeters away.

This design is, in principle, simple. It substitutes the antenna and PAin the external case for the original cell phone antenna. The externalcase antenna is directional while the cell phone antenna is isotropic oromni-directional. There is more space in the external case for antennaand RF amplifiers with additional power supplies. Once the cell towerreceives the necessary power Pt from the cell phone configuration withthe radiating case, it will automatically command the cell phone to emitat a lower level Pi=Pt/A, where A is the gain of the RF amplifier in thecase.

Referring to FIG. 12, the cell phone's internal antenna (1) couples withthe coupling antenna (2), and the signal is processed by the amplifiercircuit (3), driving the external case's transmission antenna (4).Passive metal shields (7) and (9) block RF from the cell phone'santenna, both reducing radiation toward the user and suppressing theantenna's radiated power. The external case circuit draws its power fromthe cell phone battery through the multi-pin connector (8). Thisexternal case embodiment can have its own battery supply, chargedthrough a connector at the bottom of the case while the cell phone'sbattery is also being charged. However, the system can also function bydrawing the power from the cell phone. Since the power draw of the cellphone transmitter will be lowered dramatically and the load shifted tothe external case antenna, the net draw of power from the battery shouldbe nearly the same as the standalone cell phone. The amplifier in theexternal case can be either the same or more powerful than the cellphone. These two batteries are intended to lengthen the period of usageof a wireless phone.

FIG. 13 shows an additional embodiment using multiband antennae, one oneach side of the battery or a suitable large surface such a printedcircuit board (PCB) surface inside the device. The relative phasebetween these two antennae is adjustable through a microprocessor suchthat the radiation is directed away from the user. The separationbetween these two antennae can be any distance because of the control ofrelative phase between these two antennae. The phase between these twoantennae can be controlled digitally according to the frequency bandbeing used by the wireless device. The information used for the controlof the phase can be obtained from a sensor or detector that determinesthe frequency band being used. The phase difference between the twoantennae is adjusted to optimize minimum power being directed towardsthe user and directing maximum power away from the user. This digitalcontrol allows a multi-band operation with low SAR and acceptable orenhanced TRP. In FIG. 13, the antennae are tri-band antennae and arelocated on the surface of an internal PCB opposite to a ground plane.

FIG. 14 is a diagram illustrating an embodiment of the use of phasecontrol to control the phase difference between two antennae, Antenna 1and Antenna 2, so as to redirect radiation in a direction away from theuser of the wireless device (cell phone). A transmission signal sensorTx Signal Sensor detects the signal being sent to the antennae by thetransceiver of the cell phone. This Signal Sensor determines thefrequency band being used by the cell phone for communication with thecell tower (base station), and sends a corresponding signal to theMicroprocessor. The Microprocessor in turn sends a control signal to aphase controller (Phase Control), which controls the phases of theAntenna 1 and Antenna 2 to create a predetermined phase differencebetween the antennae, appropriate for the particular communicationfrequency band being used, and directing the radiation from the antennaeaway from the user.

1. An apparatus, comprising: an external case configured to be coupledto a wireless device having a case separate from the external case, theexternal case including an antenna operatively coupled to an internalantenna of the wireless device when the external case is coupled to thewireless device and the wireless device is operational, the antennaconfigured to redirect radiation away from a user of the wireless devicewhen the external case is coupled to the wireless device and when thewireless device is operational.
 2. The apparatus of claim 1, wherein theantenna is configured to redirect radiation away from the user of thewireless device such that a specific absorption rate (SAR) of thewireless device is reduced without substantially adversely affecting atotal radiation power (TRP) of the wireless device.
 3. The apparatus ofclaim 1, wherein the antenna has a plurality of parasitic elements, theplurality of parasitic elements being operatively coupled to theinternal antenna of the wireless device when the external case isphysically coupled to the wireless device and when the wireless deviceis operational.
 4. The apparatus of claim 1, wherein the antenna is apassive antenna array that includes at least one of (1) loops, (2) Yagielements, (3) planar antennas, or (4) strip antennas.
 5. The apparatusof claim 1, wherein the wireless device is disposed between the externalcase and the user of the wireless device when the external case iscoupled to the wireless device and when the wireless device isoperational.
 6. The apparatus of claim 1, wherein the antenna includes aplurality of elements that collectively define a directionality of theantenna, the antenna configured to redirect radiation away from the userof the wireless device based on the directionality of the antenna.
 7. Anapparatus, comprising: an external case configured to be disposed with awireless device, the external case having an antenna, the antenna beingoperatively coupled to an internal antenna of the wireless device suchthat a specific absorption rate (SAR) of the wireless device is reducedwithout substantially adversely affecting a total radiation power (TRP)of the wireless device, when the external case is coupled to thewireless device and when the wireless device is operational.
 8. Theapparatus of claim 7, wherein the antenna operatively coupled to theinternal antenna of the wireless device such that radiation emitted fromthe internal antenna is redirected away from a user of the wirelessdevice, when the external case is coupled to the wireless device andwhen the wireless device is operational.
 9. The apparatus of claim 7,wherein the antenna has a plurality of parasitic elements, the pluralityof parasitic elements being operatively coupled to the internal antennaof the wireless device when the external case is physically coupled tothe wireless device and when the wireless device is operational.
 10. Theapparatus of claim 7, wherein the antenna is a passive antenna arraythat includes at least one of (1) loops, (2) Yagi elements, (3) planarantennas, or (4) strip antennas.
 11. The apparatus of claim 7, whereinthe wireless device is disposed between the external case and the userof the wireless device when the external case is coupled to the wirelessdevice and when the wireless device is operational.
 12. The apparatus ofclaim 7, wherein the antenna includes a plurality of elements thatcollectively define a directionality of the antenna, the antennaoperatively coupled to the internal antenna of the wireless device suchthat radiation emitted from the internal antenna is redirected away froma user of the wireless device based on the directionality of theantenna.
 13. A method comprising: passively coupling radiation, from aninternal antenna of a wireless device having a case, at an external casewhen the external case is coupled to the wireless device and when thewireless device is operational, the external case being separate fromthe case of the wireless device; and redirecting the radiation away froma user of the wireless device when the external case is coupled to thewireless device and when the wireless device is operational.
 14. Themethod of claim 13, wherein the redirecting includes redirecting theradiation such that a specific absorption rate (SAR) of the wirelessdevice is reduced without substantially adversely affecting a totalradiation power (TRP) of the wireless device.
 15. The method of claim13, wherein the redirecting includes: reducing a specific absorptionrate (SAR) of the wireless device; and substantially maintaining a totalradiation power (TRP) of the wireless device.
 16. The method of claim13, wherein the external case includes an antenna array, the antennaarray being operatively coupled to the internal antenna of the wirelessdevice when the external case is physically coupled to the wirelessdevice and when the wireless device is operational.
 17. The method ofclaim 13, wherein: the external case includes an antenna having aplurality of parasitic elements, the passively coupling radiationincluding passively coupling radiation at the plurality of parasiticelements that are operatively coupled to the internal antenna of thewireless device when the external case is physically coupled to thewireless device and when the wireless device is operational.
 18. Themethod of claim 13, wherein: the external case includes a passiveantenna array that includes at least one of (1) loops, (2) Yagielements, (3) planar antennas or (4) strip antennas, the passivelycoupling radiation including passively coupling radiation at the passiveantenna array that is operatively coupled to the internal antenna of thewireless device when the external case is physically coupled to thewireless device and when the wireless device is operational.
 19. Themethod of claim 13, wherein the wireless device is disposed between theexternal case and the user of the wireless device when the external caseis coupled to the wireless device and when the wireless device isoperational.
 20. The method of claim 13, wherein: the external caseincludes an antenna having a plurality of elements that collectivelydefine a directionality of the antenna, the passively coupling radiationincluding passively coupling radiation at the antenna that isoperatively coupled to the internal antenna of the wireless device whenthe external case is physically coupled to the wireless device and whenthe wireless device is operational, the redirecting includingredirecting radiation away from the user of the wireless device based onthe directionality of the antenna.